Working with File-Based External Tables

External tables provide access to data stored in data sources outside of HAWQ as if the data were stored in regular database tables. Data can be read from or written to external tables.

An external table is a HAWQ database table backed with data that resides outside of the database. An external table is either readable or writable. It can be used like a regular database table in SQL commands such as SELECT and INSERT and joined with other tables. External tables are most often used to load and unload database data.